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PURPOSE To evaluate long-term morbidity and mortality among unilateral, nonsyndromic Wilms tumor (WT) survivors according to conventional treatment regimens. METHODS Cumulative incidence of late mortality (≥ 5 years from diagnosis) and chronic health conditions (CHCs) were evaluated in WT survivors from the Childhood Cancer Survivor Study. Outcomes were evaluated by treatment, including nephrectomy combined with vincristine and actinomycin D (VA), VA + doxorubicin + abdominal radiotherapy (VAD + ART), VAD + ART + whole lung radiotherapy, or receipt of ≥ 4 chemotherapy agents. RESULTS Among 2,008 unilateral WT survivors, 142 deaths occurred (standardized mortality ratio, 2.9, 95% CI, 2.5 to 3.5; 35-year cumulative incidence of death, 7.8%, 95% CI, 6.3 to 9.2). The 35-year cumulative incidence of any grade 3-5 CHC was 34.1% (95% CI, 30.7 to 37.5; rate ratio [RR] compared with siblings 3.0, 95% CI, 2.6 to 3.5). Survivors treated with VA alone had comparable risk for all-cause late mortality relative to the general population (standardized mortality ratio, 1.0; 95% CI, 0.5 to 1.7) and modestly increased risk for grade 3-5 CHCs compared with siblings (RR, 1.5; 95% CI, 1.1 to 2.0), but remained at increased risk for intestinal obstruction (RR, 9.4; 95% CI, 3.9 to 22.2) and kidney failure (RR, 11.9; 95% CI, 4.2 to 33.6). Magnitudes of risk for grade 3-5 CHCs, including intestinal obstruction, kidney failure, premature ovarian insufficiency, and heart failure, increased by treatment group intensity. CONCLUSION With approximately 40% of patients with newly diagnosed WT currently treated with VA alone, the burden of late mortality/morbidity in future decades is projected to be lower than that for survivors from earlier eras. Nevertheless, the risk of late effects such as intestinal obstruction and kidney failure was elevated across all treatment groups, and there was a dose-dependent increase in risk for all grade 3-5 CHCs by treatment group intensity.

PURPOSE Interindividual variability in the dose-dependent association between anthracyclines and cardiomyopathy suggests a modifying role of genetic susceptibility. Few previous studies have examined gene-anthracycline interactions. We addressed this gap using the Childhood Cancer Survivor Study (discovery) and the Children's Oncology Group (COG) study COG-ALTE03N1 (replication). METHODS A genome-wide association study (Illumina HumanOmni5Exome Array) in 1,866 anthracycline-exposed Childhood Cancer Survivor Study participants (126 with heart failure) was used to identify single-nucleotide polymorphisms (SNPs) with either main or gene-environment interaction effect on anthracycline-related cardiomyopathy that surpassed a prespecified genome-wide threshold for statistical significance. We attempted replication in a matched case-control set of anthracycline-exposed childhood cancer survivors with (n = 105) and without (n = 160) cardiomyopathy from COG-ALTE03N1. RESULTS Two SNPs (rs17736312 [ ROBO2]) and rs113230990 (near a CCCTC-binding factor insulator [< 750 base pair]) passed the significance cutoff for gene-anthracycline dose interaction in discovery. SNP rs17736312 was successfully replicated. Compared with the GG/AG genotypes on rs17736312 and anthracyclines ≤ 250 mg/m2, the AA genotype and anthracyclines > 250 mg/m2 conferred a 2.2-fold (95% CI, 1.2 to 4.0) higher risk of heart failure in discovery and an 8.2-fold (95% CI, 2.0 to 34.4) higher risk in replication. ROBO2 encodes transmembrane Robo receptors that bind Slit ligands (SLIT). Slit-Robo signaling pathway promotes cardiac fibrosis by interfering with the transforming growth factor-β1/small mothers against decapentaplegic (Smad) pathway, resulting in disordered remodeling of the extracellular matrix and potentiating heart failure. We found significant gene-level associations with heart failure: main effect ( TGF-β1, P = .007); gene*anthracycline interaction ( ROBO2*anthracycline, P = .0003); and gene*gene*anthracycline interaction ( SLIT2* TGF-β1*anthracycline, P = .009). CONCLUSION These findings suggest that high-dose anthracyclines combined with genetic variants involved in the profibrotic Slit-Robo signaling pathway promote cardiac fibrosis via the transforming growth factor-β1/Smad pathway, providing credence to the biologic plausibility of the association between SNP rs17736312 ( ROBO2) and anthracycline-related cardiomyopathy.

PURPOSE To describe the risk of late mortality, subsequent malignant neoplasms (SMNs), and chronic health conditions (CHCs) in survivors of neuroblastoma diagnosed in infancy by treatment era and exposures. METHODS Among 5-year survivors of neuroblastoma in the Childhood Cancer Survivor Study diagnosed age < 1 year between 1970 and 1999, we examined the cumulative incidence of late (> 5 years from diagnosis) mortality, SMN, and CHCs (grades 2-5 and 3-5). Multivariable Cox regression models estimated hazard ratios (HRs) and 95% CIs by decade and treatment (surgery-alone v chemotherapy with or without surgery [C ± S] v radiation with or without chemotherapy ± surgery [R ± C ± S]) among survivors and between survivors and 5,051 siblings. RESULTS Among 1,397 eligible survivors, the 25-year cumulative incidence of late mortality was 2.1% (95% CI, 1.3 to 3.9) with no difference by treatment era. Among 990 participants who completed a baseline survey, fewer survivors received radiation in more recent eras (51.2% 1970s, 20.4% 1980s, and 10.1% 1990s; P < .001). Risk of SMN was elevated only among individuals treated with radiation-containing regimens compared with surgery alone (HR[C ± S], 3.2 [95% CI, 0.9 to 11.6]; HR[R ± C ± S], 5.7 [95% CI, 1.2 to 28.1]). In adjusted models, there was a 50% reduction in risk of grade 3-5 CHCs in the 1990s versus 1970s (HR, 0.5 [95% CI, 0.3 to 0.9]; P = .01); individuals treated with radiation had a 3.6-fold risk for grade 3-5 CHCs (95% CI, 2.1 to 6.2) versus those treated with surgery alone. When compared with siblings, risk of grade 3-5 CHCs for survivors was lowest in the most recent era (HR[1970s], 4.7 [95% CI, 3.4 to 6.5]; HR[1980s], 4.6 [95% CI, 3.3 to 6.4]; HR[1990s], 2.5 [95% CI, 1.7 to 3.9]). CONCLUSION Neuroblastoma survivors treated during infancy have a relatively low absolute burden of late mortality and SMN. Encouragingly, risk of CHCs has declined in more recent eras with reduced exposure to radiation therapy.

PURPOSE To evaluate the outcomes and cost-effectiveness of the Children's Oncology Group Guideline recommendation for breast cancer (BC) screening using mammography (MAM) and breast magnetic resonance imaging (MRI) in female chest-irradiated childhood Hodgkin lymphoma (HL) survivors. Digital breast tomosynthesis (DBT), increasingly replacing MAM in practice, was also examined. METHODS Life years (LYs), quality-adjusted LYs (QALYs), BC mortality, health care costs, and false-positive screen frequencies of undergoing annual MAM, DBT, MRI, MAM + MRI, and DBT + MRI from age 25 to 74 years were estimated by microsimulation. BC risks and non-BC mortality were estimated from female 5-year survivors of HL in the Childhood Cancer Survivor Study and the US population. Test performance of MAM and MRI was synthesized from HL studies, and that of DBT from the general population. Costs (2017 US dollars [USD]) and utility weights were obtained from the medical literature. Incremental cost-effectiveness ratios (ICERs) were calculated. RESULTS With 100% screening adherence, annual BC screening extended LYs by 0.34-0.46 years over no screening. If the willingness-to-pay threshold to gain a quality-adjusted LY was ICER < $100,000 USD, annual MAM at age 25-74 years was the only cost-effective strategy. When nonadherence was taken into consideration, only annual MAM at age 30-74 years (ICER = $56,972 USD) was cost-effective. Supplementing annual MAM with MRI costing $545 USD was not cost-effective under either adherence condition. If MRI costs were reduced to $300 USD, adding MRI to annual MAM at age 30-74 years could become more cost-effective, particularly in the reduced adherence condition (ICER = $133,682 USD). CONCLUSION Annual BC screening using MAM at age 30-74 years is effective and cost-effective in female chest-irradiated HL survivors. Although annual adjunct MRI is not cost-effective at $545 USD cost, it could become cost-effective as MRI cost is reduced, a plausible scenario with the emergent use of abbreviated MRI.

PURPOSE Cancer survivors develop cancer and treatment-related morbidities at younger than normal ages and are at risk for early mortality, suggestive of an aging phenotype. The Cumulative Illness Rating Scale for Geriatrics (CIRS-G) is specifically designed to describe the accumulation of comorbidities over time with estimates of severity such as total score (TS) which is a sum of possible conditions weighted by severity. These severity scores can then be used to predict future mortality. METHODS CIRS-G scores were calculated in cancer survivors and their siblings from Childhood Cancer Survivor Study cohort members from two time points 19 years apart and members of the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2004. CIRS-G metrics were analyzed using Cox proportional hazards regression to determine subsequent mortality risk. RESULTS In total, 14,355 survivors with a median age of 24 (IQR, 18-30) years and 4,022 siblings with a median age of 26 (IQR, 19-33) years provided baseline data; 6,138 survivors and 1,801 siblings provided follow-up data. Cancer survivors had higher median baseline TS than siblings at baseline (5.75 v 3.44) and follow-up (7.76 v 4.79), all P < .01. The mean increase in TS from baseline to follow-up was significantly steeper in cancer survivors (2.89 males and 3.18 females) vs. siblings (1.79 males and 1.69 females) and NHANES population (2.0 males and 1.94 females), all P < .01. Every point increase in baseline TS increased hazard for death by 9% (95% CI, 8 to 10) among survivors. CONCLUSION Application of a geriatric rating scale to characterize disease supports the hypothesis that morbidity accumulation is accelerated in young adult survivors of childhood cancer when compared with siblings and the general population.

The association between individual-level poverty and relapse in children receiving maintenance treatment for acute lymphoblastic leukemia (ALL) remains unclear. In a secondary analysis of COG-AALL03N1, we used data from US Census Bureau to categorize patients living below year-specific federal poverty thresholds, calculated using self-reported annual household income and size of household. Participants living 120% below federal poverty thresholds were categorized as living in extreme poverty. Hazard of relapse was estimated using multivariable proportional subdistributional hazards regression for patients living in extreme poverty while receiving ALL maintenance therapy after adjusting for relevant predictors. Among 592 patients in this analysis, 12.3% of the patients were living in extreme poverty. After a median follow-up of 7.9y, the cumulative incidence of relapse at 3y from study enrollment among those living in extreme poverty was significantly higher (14.3%, 95% confidence interval [CI]= 7.3-23.6) compared to those not living in extreme poverty (7.6%, 95%CI=5.5-10.1, P=0.04). Multivariable analysis demonstrated that children living in extreme poverty had a 1.95-fold greater hazard of relapse (95%CI=1.03-3.72, P=0.04) compared to those not living in extreme poverty; this association was mitigated after inclusion of race/ethnicity in the model (hazard ratio=1.68, 95%CI=0.86-3.28, P=0.1), likely due to collinearity between race/ethnicity and poverty. A greater proportion of children living in extreme poverty were non-adherent to mercaptopurine (57.1% vs 40.9%, P=0.04); however, poor adherence did not completely explain the association between poverty and relapse risk. Future studies need to understand the mechanisms underlying the association between extreme poverty and relapse risk. Clinical Trial number: NCT00268528.

PDF file - 283K, Comparison of Oragene to mouthwash telomere length in six individuals, with varying degrees of correlation. Samples from healthy subjects were compared to a sample from a subject with a diagnosis of dyskeratosis congenita, a short telomere syndrome (labeled BMF5).

PDF file - 62K, Additional detail with regard to the source of DNA and methods for DNA isolation, as well as methods for quantitative PCR in estimating telomere content, are provided.

Supplementary Figure 2 shows the exome coverage achieved with whole exome sequencing.

PDF file - 329K, Comparison cell types collected from three different methods, buccal brush, mouthwash, and saliva. Saliva demonstrated the highest degree of variability from sample to sample, with the mean percentage of epithelial cells and lymphocytes approximately equal.

Legend for Supplementary Figures, Table and Files

PDF file - 82K

Purpose: Shorter constitutional telomere length has been associated with increased cancer incidence. Furthermore, telomere shortening is observed in response to intensive chemotherapy and/or ionizing radiation exposure. We aimed to determine whether less telomere content was associated with treatment-related second malignant neoplasms (SMN) in childhood cancer survivors.Experimental Design: Using a nested case–control design, 147 cancer survivors with breast cancer, thyroid cancer, or sarcoma developing after treatment for childhood cancer (cases) were matched (1:1) with childhood cancer survivors without a SMN (controls). Cases and controls were matched by primary cancer diagnosis, years since diagnosis, age at the time of sample collection, years of follow-up from childhood cancer diagnosis, exposure to specific chemotherapy agents, and to specific radiation fields. We performed conditional logistic regression using telomere content as a continuous variable to estimate ORs with corresponding 95% confidence intervals (CI) for development of SMN. ORs were also estimated for specific SMN types, i.e., breast cancer, thyroid cancer, and sarcoma.Results: There was an inverse relationship between telomere content and SMN, with an adjusted OR of 0.3 per unit change in telomere length to single-copy gene ratio (95% CI, 0.09–1.02; P = 0.05). Patients with thyroid cancer SMN were less likely to have more telomere content (OR, 0.04; 95% CI, 0.00–0.55; P = 0.01), but statistically significant associations could not be demonstrated for breast cancer or sarcoma.Conclusions: A relation between less telomere content and treatment-related thyroid cancer was observed, suggesting that shorter telomeres may contribute to certain SMNs in childhood cancer survivors. Clin Cancer Res; 20(4); 904–11. ©2013 AACR.

Supplementary Figure 5:Germline TP53 variants in the validation cohort Sanger sequencing-derived electropherograms displaying the germline variant in Exon 4 are shown.

Background: Although ionizing radiation is an established environmental risk factor for thyroid cancer, the effect of chemotherapy drugs on thyroid cancer risk remains unclear. We evaluated the chemotherapy-related risk of thyroid cancer in childhood cancer survivors and the possible joint effects of chemotherapy and radiotherapy.Methods: The study included 12,547 five-year survivors of childhood cancer diagnosed during 1970 through 1986. Chemotherapy and radiotherapy information was obtained from medical records, and radiation dose was estimated to the thyroid gland. Cumulative incidence and relative risks were calculated with life-table methods and Poisson regression. Chemotherapy-related risks were evaluated separately by categories of radiation dose.Results: Histologically confirmed thyroid cancer occurred in 119 patients. Thirty years after the first childhood cancer treatment, the cumulative incidence of thyroid cancer was 1.3% (95% CI, 1.0–1.6) for females and 0.6% (0.4–0.8) for males. Among patients with thyroid radiation doses of 20 Gy or less, treatment with alkylating agents was associated with a significant 2.4-fold increased risk of thyroid cancer (95% CI, 1.3–4.5; P = 0.002). Chemotherapy risks decreased as radiation dose increased, with a significant decrease for patients treated with alkylating agents (Ptrend = 0.03). No chemotherapy-related risk was evident for thyroid radiation doses more than 20 Gy.Conclusions: Treatments with alkylating agents increased thyroid cancer risk, but only in the radiation dose range less than 20 Gy, in which cell sparing likely predominates over cell killing.Impact: Our study adds to the evidence for chemotherapy agent–specific increased risks of thyroid cancer, which to date, were mainly thought to be related to prior radiotherapy. Cancer Epidemiol Biomarkers Prev; 21(1); 92–101. ©2011 AACR.

Purpose: Second malignant neoplasms (SMNs) are severe late complications that occur in pediatric cancer survivors exposed to radiotherapy and other genotoxic treatments. To characterize the mutational landscape of treatment-induced sarcomas and to identify candidate SMN-predisposing variants, we analyzed germline and SMN samples from pediatric cancer survivors.Experimental Design: We performed whole-exome sequencing (WES) and RNA sequencing on radiation-induced sarcomas arising from two pediatric cancer survivors. To assess the frequency of germline TP53 variants in SMNs, Sanger sequencing was performed to analyze germline TP53 in 37 pediatric cancer survivors from the Childhood Cancer Survivor Study (CCSS) without any history of a familial cancer predisposition syndrome but known to have developed SMNs.Results: WES revealed TP53 mutations involving p53′s DNA-binding domain in both index cases, one of which was also present in the germline. The germline and somatic TP53-mutant variants were enriched in the transcriptomes for both sarcomas. Analysis of TP53-coding exons in germline specimens from the CCSS survivor cohort identified a G215C variant encoding an R72P amino acid substitution in 6 patients and a synonymous SNP A639G in 4 others, resulting in 10 of 37 evaluable patients (27%) harboring a germline TP53 variant.Conclusions: Currently, germline TP53 is not routinely assessed in patients with pediatric cancer. These data support the concept that identifying germline TP53 variants at the time a primary cancer is diagnosed may identify patients at high risk for SMN development, who could benefit from modified therapeutic strategies and/or intensive posttreatment monitoring. Clin Cancer Res; 23(7); 1852–61. ©2016 AACR.

Supplementary Figure 1: Radiotherapy-induced sarcomas in pediatric cancer survivors Radiation dosimetry, imaging and histology are shown.

Supplementary File 1. SNVs for Patient 1's SMN;Supplementary File 2. SNVs for Patient 2's SMN;Supplementary File 3. List of dinucleotide substitutions;Supplementary File 4. TP53 germline sequencing primers

CCR Translation for This Article from Telomere Content and Risk of Second Malignant Neoplasm in Survivors of Childhood Cancer: A Report from the Childhood Cancer Survivor Study

Supplementary Figure 4 displays Copy number alterations and allele frequencies across all chromosomes for SMNs.

Supplementary Table 1. Treatment exposures and TP53 Variant status in the Validation cohort Tumor, TP53 variant status (G215C, A639G), and treatment exposure details are shown for each validation sample (VS).

Supplementary Figure 3: Somatic variants in radiation-induced SMNs Frequencies of specific types of base substitutions in SNVs (synonymous and non-synonymous SNVs) pooled from all samples are shown.

Background: Survivors of childhood cancer are at risk for therapy-related subsequent malignant neoplasms (SMN), including thyroid SMN. Telomere length (TL) is associated with cancer risk, but the relationship between TL and SMN risk among survivors is less clear. Methods: We conducted a nested, matched case–control study of radiation-exposed 15-year+ adult survivors of childhood cancer with thyroid SMN (cases) and without SMN (controls). Forty-six cases were matched to 46 controls by primary diagnosis, chemotherapy (yes/no), radiation field, and follow-up duration. Lymphocyte TL (LTL) was measured by telomere flow-FISH cytometry using blood samples banked at a mean of 38.9 years (cases), 39.2 years (controls). Genetic variation in telomere genes was assessed by whole genome sequencing. Point estimates for LTL Results: Cases had shorter median LTL than controls in three out of four leukocyte subsets. Cases were more likely to have NK cell LTL Conclusions: Long-term survivors have shorter than expected LTL, a finding that is more pronounced among survivors with thyroid SMN. Impact: The long-term impact of childhood cancer treatment on immune function is poorly understood. Our findings support immune function studies in larger survivor cohorts to assess long-term deficits in adaptive and innate immunity that may underlie SMN risk.

Background: Prior studies have identified that survivors of childhood acute lymphoblastic leukemia (ALL) report poor health status. It is unknown how risk-stratified therapy impacts the health status of ALL survivors. Methods: We estimated and compared the prevalence of self-reported poor health status among adult (≥18 years) survivors of childhood ALL diagnosed at age Results: Among 5,119 survivors and 4,693 siblings, survivors were more likely to report poor health status in each domain including poor general health (13.5% vs. 7.4%; PR = 1.92; 95% CI, 1.69–2.19). Compared with 70s, 90sSR and 90sHR were less likely to report poor general health (90sSR: PR = 0.75; 95% CI, 0.57–0.98; 90sHR: PR = 0.58; 95% CI, 0.39–0.87), functional impairment (90sSR: PR = 0.56; 95% CI, 0.42–0.76; 90sHR: PR = 0.63; 95% CI, 0.42–0.95), and activity limitations (90sSR: 0.61; 95% CI, 0.45–0.83; 90sHR: PR = 0.59; 95% CI, 0.38–0.91). An added adjustment for chronic conditions in multivariable models partially attenuated 90sSR risk estimates. Conclusions: Risk-stratified ALL therapy has succeeded in reducing risk for poor general health, functional impairment, and activity limitations among more recent survivors of standard- and high-risk therapy. Impact: Future research into the relationship between risk-stratified therapy, health status, and late health outcomes may provide new opportunities to further improve late morbidity among survivors.

Background: Lung cancer, the most common cause of cancer-related death in adults, has not been well studied as a subsequent malignant neoplasm (SMN) in childhood cancer survivors. We assessed prevalence, risk factors, and outcomes for lung SMN in the Childhood Cancer Survivor Study (CCSS) cohort. Methods: Among 25,654 5-year survivors diagnosed with childhood cancer ( Results: Forty-two survivors developed a lung SMN [SIR, 4.0; 95% confidence interval (CI), 2.9–5.4] with a cumulative incidence of 0.16% at 30 years from diagnosis (95% CI, 0.09%–0.23%). In a treatment model, chest radiation doses of 10–30 Gy (HR, 3.4; 95% CI, 1.05–11.0), >30–40 Gy (HR, 4.6; 95% CI, 1.5–14.3), and >40 Gy (HR, 9.1; 95% CI, 3.1–27.0) were associated with lung SMN, with a monotone dose trend (Ptrend < 0.001). Survivors of Hodgkin lymphoma (SIR, 9.3; 95% CI, 6.2–13.4) and bone cancer (SIR, 4.4; 95% CI, 1.8–9.1) were at greatest risk for lung SMN. Conclusions: Survivors of childhood cancer are at increased risk for lung cancer compared with the general population. Greatest risk was observed among survivors who received chest radiotherapy or with primary diagnoses of Hodgkin lymphoma or bone cancer. Impact: This study describes the largest number of observed lung cancers in childhood cancer survivors and elucidates need for further study in this aging and growing population.

Interindividual variability in the dose-dependent association between anthracyclines and cardiomyopathy suggests a modifying role of genetic susceptibility. Few previous studies have examined gene-anthracycline interactions. We addressed this gap using the Childhood Cancer Survivor Study (discovery) and the Children's Oncology Group (COG) study COG-ALTE03N1 (replication).A genome-wide association study (Illumina HumanOmni5Exome Array) in 1,866 anthracycline-exposed Childhood Cancer Survivor Study participants (126 with heart failure) was used to identify single-nucleotide polymorphisms (SNPs) with either main or gene-environment interaction effect on anthracycline-related cardiomyopathy that surpassed a prespecified genome-wide threshold for statistical significance. We attempted replication in a matched case-control set of anthracycline-exposed childhood cancer survivors with (n = 105) and without (n = 160) cardiomyopathy from COG-ALTE03N1.Two SNPs (rs17736312 [These findings suggest that high-dose anthracyclines combined with genetic variants involved in the profibrotic Slit-Robo signaling pathway promote cardiac fibrosis via the transforming growth factor-β1/Smad pathway, providing credence to the biologic plausibility of the association between SNP rs17736312 (

Five-year survival following childhood acute myeloid leukemia (AML) has increased following improvements in treatment and supportive care. Long-term health outcomes are unknown. To address this, cumulative incidence of late mortality and grades 3 to 5 chronic health condition (CHC) were estimated among 5-year AML survivors diagnosed between 1970 and 1999. Survivors were compared by treatment group (hematopoietic cell transplantation [HCT], chemotherapy with cranial radiation [chemo + CRT], chemotherapy only [chemo-only]), and diagnosis decade. Self-reported health status was compared across treatments, diagnosis decade, and with siblings. Among 856 survivors (median diagnosis age, 7.1 years; median age at last follow-up, 29.4 years), 20-year late mortality cumulative incidence was highest after HCT (13.9%; 95% confidence interval [CI], 10.0%-17.8%; chemo + CRT, 7.6%; 95% CI, 2.2%-13.1%; chemo-only, 5.1%; 95% CI, 2.8%-7.4%). Cumulative incidence of mortality for HCT survivors diagnosed in the 1990s (8.5%; 95% CI, 4.1%-12.8%) was lower vs those diagnosed in the 1970s (38.9%; 95% CI, 16.4%-61.4%). Most survivors did not experience any grade 3 to 5 CHC after 20 years (HCT, 45.8%; chemo + CRT, 23.7%; chemo-only, 27.0%). Furthermore, a temporal reduction in CHC cumulative incidence was seen after HCT (1970s, 76.1%; 1990s, 38.3%; P = .02), mirroring reduced use of total body irradiation. Self-reported health status was good to excellent for 88.2% of survivors; however, this was lower than that for siblings (94.8%; P < .0001). Although HCT is associated with greater long-term morbidity and mortality than chemotherapy-based treatment, gaps have narrowed, and all treatment groups report favorable health status.

Obesity at diagnosis of childhood acute lymphoblastic leukemia (ALL) is associated with greater risk of relapse; whether this association extends to obesity during maintenance is unstudied.This study used data from AALL03N1 to calculate median body mass index (BMI) for 676 children over 6 consecutive months during maintenance therapy; BMI percentile (BMI%ile) were operationalized as normal/underweight (85%ile), overweight/obese (85%-98%ile), and extreme obesity (≥99%ile). Hazard of relapse was estimated using multivariable proportional subdistributional hazards regression after adjusting for all relevant demographic and clinical predictors.Median age at study enrollment was 6 years and median length of follow-up was 7.9 years. Overall, 43.3% of the cohort was underweight/normal weight, 44.8% was overweight/obese, and 11.8% had extreme obesity. Cumulative incidence of relapse at 4 years from study enrollment was higher among those with extreme obesity (13.6% ± 4.5%) compared to those with underweight/normal weight (9.0% ± 2.1%). Multivariable analysis revealed that children with extreme obesity had a 2.4-fold (95% confidence interval [CI], 1.1-5.0; p = .01) greater hazard of relapse compared to those who were underweight/normal weight. Overweight/obese patients were at comparable risk to those who were underweight/normal weight (hazard ratio, 0.8; 95% CI, 0.4-1.6). Erythrocyte thioguanine nucleotide (TGN) levels were significantly lower among children with extreme obesity compared to those with underweight/normal weight (141.6 vs. 168.8 pmol/8 × 10Extreme obesity during maintenance therapy is associated with greater hazard of relapse in children with ALL. Underlying mechanisms of this association needs further investigation.Findings from this study demonstrate that extreme obesity during maintenance therapy is associated with a greater hazard of relapse among children with acute lymphoblastic leukemia. We show that children with obesity have lower levels of erythrocyte thioguanine nucleotides even after adjusting for adherence to oral chemotherapy. However, these lower levels do not explain the greater hazard of relapse, paving the way for future studies to explore this association.

PURPOSE Radiotherapy for childhood cancer is associated with elevated subsequent neoplasm (SN) risk, but the contribution of rare variants in DNA damage response and radiation sensitivity genes to SN risk is unknown. PATIENTS AND METHODS We conducted whole-exome sequencing in a cohort of childhood cancer survivors originally diagnosed during 1970 to 1986 (mean follow-up, 32.7 years), with reconstruction of doses to body regions from radiotherapy records. We identified patients who developed SN types previously reported to be related to radiotherapy (RT-SNs; eg, basal cell carcinoma [BCC], breast cancer, meningioma, thyroid cancer, sarcoma) and matched controls (sex, childhood cancer type/diagnosis, age, SN location, radiation dose, survival). Conditional logistic regression assessed SN risk associated with potentially protein-damaging rare variants (SnpEff, ClinVar) in 476 DNA damage response or radiation sensitivity genes with exact permutation-based P values using a Bonferroni-corrected significance threshold of P < 8.06 × 10−5. RESULTS Among 5,105 childhood cancer survivors of European descent, 1,108 (21.7%) developed at least 1 RT-SN. Out-of-field RT-SN risk, excluding BCC, was associated with homologous recombination repair (HRR) gene variants (patient cases, 23.2%; controls, 10.8%; odds ratio [OR], 2.6; 95% CI, 1.7 to 3.9; P = 4.79 × 10−5), most notably but nonsignificantly for FANCM (patient cases, 4.0%; matched controls, 0.6%; P = 9.64 × 10−5). HRR variants were not associated with likely in/near-field RT-SNs, excluding BCC (patient cases, 12.7%; matched controls, 12.9%; P = .92). Irrespective of radiation dose, risk for RT-SNs was also associated with EXO1 variants (patient cases, 1.8%; controls, 0.4%; P = 3.31 × 10−5), another gene implicated in DNA double-strand break repair. CONCLUSION In this large-scale discovery study, we identified novel associations between RT-SN risk after childhood cancer and potentially protein-damaging rare variants in genes involved in DNA double-strand break repair, particularly HRR. With replication, these results could affect screening recommendations for childhood cancer survivors and risk-benefit assessments of treatment approaches.

Background Early initiation of breast cancer screening is recommended for high-risk women, including survivors of childhood cancer treated with chest radiation. Recent studies suggest that female survivors of childhood leukemia or sarcoma treated without chest radiation are also at elevated early onset breast cancer risk. However, the potential clinical benefits and cost-effectiveness of early breast cancer screening among these women are uncertain. Methods Using data from the Childhood Cancer Survivor Study, we adapted 2 Cancer Intervention and Surveillance Modeling Network simulation models to reflect the elevated risks of breast cancer and competing mortality among leukemia and sarcoma survivors. Costs and utility weights were based on published studies and databases. Outcomes included breast cancer deaths averted, false-positive screening results, benign biopsies, and incremental cost-effectiveness ratios. Results In the absence of screening, the lifetime risk of dying from breast cancer among survivors was 6.8% to 7.0% across models. Early initiation of annual mammography with breast magnetic resonance imaging screening between ages 25 and 40 years would avert 52.6% to 64.3% of breast cancer deaths. When costs and quality-of-life impacts were considered, screening starting at age 40 years was the only strategy with an incremental cost-effectiveness ratio below the $100 000 per quality-adjusted life-year (QALY) gained cost-effectiveness threshold ($27 680 to $44 380 per QALY gained across models). Conclusions Among survivors of childhood leukemia or sarcoma, early initiation of breast cancer screening at age 40 years may reduce breast cancer deaths by half and is cost-effective. These findings could help inform screening guidelines for survivors treated without chest radiation.

PurposeThe International Consortium for Pooled Studies on Subsequent Malignancies after Childhood and Adolescent Cancer was established in 2018 to address gaps in knowledge of risk and risk factors for breast cancer subsequent to childhood/adolescent cancer by pooling individual patient data from seven cohorts. Initially, the pooled cohort will focus on three clinically relevant questions regarding treatment-related subsequent breast cancer risk in female survivors, which are the risk related to low-dose radiotherapy exposure to the chest, specific chemotherapy agents and attained age.ParticipantsThe consortium database includes pooled data on 21 892 female survivors from seven cohorts in North America and Europe with a primary cancer diagnosis at Findings to dateThis is a newly established pooled study. The cohort profile summarised the data collected from each included cohort, including childhood cancer diagnosis information and treatment details (ie, radiotherapy fields and cumulative doses, and chemotherapy agents and cumulative doses for each agent). Included cohorts’ follow-up started 1951–1981 and ended 2013–2021, respectively, for a median follow-up duration of 24.3 (IQR 18.0–32.8) years since primary cancer diagnosis. The median age at primary cancer diagnosis was 5.4 (IQR 2.5–11.9) years. And the median attained age at last follow-up was 32.2 (IQR 24.0–40.4) years. In all, 4240 (19.4%) survivors were treated with radiotherapy to the chest and 9308 (42.5%) with anthracyclines. At the end of the follow-up, 835 females developed a first subsequent breast cancer, including 635 invasive breast cancer only, 184 carcinomas in situ only (172 ductal carcinomas in situ and 12 lobular carcinomas in situ), and 16 with both an invasive and in situ diagnosis at the same moment. The cumulative incidences of subsequent breast cancer (both invasive and in situ) 25 and 35 years after primary cancer diagnosis were 2.2% and 6.2%, respectively.Future plansThe consortium is intended to serve as a model and robust source of childhood/adolescent cancer survivor data for elucidating other knowledge gaps on subsequent breast cancer risk, and risk of other subsequent malignancies (including data on males) in the future.

ImportanceBreast cancer is the most common invasive subsequent malignant disease in childhood cancer survivors, though limited data exist on changes in breast cancer rates as primary cancer treatments have evolved.ObjectiveTo quantify the association between temporal changes in cancer treatment over 3 decades and subsequent breast cancer risk.Design, Setting, and ParticipantsRetrospective cohort study of 5-year cancer survivors diagnosed when younger than 21 years between 1970 and 1999, with follow-up through December 5, 2020.ExposuresRadiation and chemotherapy dose changes over time.Main Outcomes and MeasuresBreast cancer cumulative incidence rates and age-specific standardized incidence ratios (SIRs) compared across treatment decades (1970-1999). Piecewise exponential models estimated invasive breast cancer and ductal carcinoma in situ (DCIS) risk and associations with treatment exposures, adjusted for age at childhood cancer diagnosis and attained age.ResultsAmong 11 550 female survivors (median age, 34.2 years; range 5.6-66.8 years), 489 developed 583 breast cancers: 427 invasive, 156 DCIS. Cumulative incidence was 8.1% (95% CI, 7.3%-9.0%) by age 45 years. An increased breast cancer risk (SIR, 6.6; 95% CI, 6.1-7.2) was observed for survivors compared with the age-sex-calendar-year-matched general population. Changes in therapy by decade included reduced rates of chest (34% in the 1970s, 22% in the 1980s, and 17% in the 1990s) and pelvic radiotherapy (26%, 17%, and 13% respectively) and increased rates of anthracycline chemotherapy exposures (30%, 51%, and 64%, respectively). Adjusting for age and age at diagnosis, the invasive breast cancer rate decreased 18% every 5 years of primary cancer diagnosis era (rate ratio [RR], 0.82; 95% CI, 0.74-0.90). When accounting for chest radiotherapy exposure, the decline attenuated to an 11% decrease every 5 years (RR, 0.89; 95% CI, 0.81-0.99). When additionally adjusted for anthracycline dose and pelvic radiotherapy, the decline every 5 years increased to 14% (RR, 0.86; 95% CI, 0.77-0.96). Although SIRs of DCIS generally increased over time, there were no statistically significant changes in incidence.Conclusions and RelevanceInvasive breast cancer rates in childhood cancer survivors have declined with time, especially in those younger than 40 years. This appears largely associated with the reduced use of chest radiation therapy, but was tempered by concurrent changes in other therapies.

ImportanceMeningioma is the most common subsequent neoplasm following cranial irradiation among survivors of childhood cancer, but there are still uncertainties regarding the magnitude of the radiation dose-response association, potential modifiers of radiation risks, and the role of chemotherapy.ObjectiveTo evaluate meningioma risk in survivors of childhood cancer following radiotherapy and chemotherapy and identify possible modifying factors of radiation-associated risk.Design, Setting, and ParticipantsThis international case-control study pooled data from 4 nested case-control studies of survivors of childhood cancer diagnosed between 1942 and 2000, followed through 2016. Cases were defined as participants diagnosed with a subsequent meningioma. Controls were matched to cases based on sex, age at first cancer diagnosis, and duration of follow-up. Data were analyzed from July 2019 to June 2022.ExposuresRadiation dose (Gy) to the meningioma site and cumulative chemotherapy doses, including intrathecal and systemic methotrexate doses.Main Outcomes and MeasuresThe main outcome was subsequent meningioma, assessed using odds ratios (ORs) and excess odds ratios per gray (EOR/Gy).ResultsThe analysis included 273 survivors of childhood cancer who developed meningioma (cases) and 738 survivors who did not (controls), with a total of 1011 individuals (median [IQR] age at first cancer diagnosis 5.0 [3.0-9.2] years; 599 [59.2%] female). Median (IQR) time since first cancer was 21.5 (15.0-27.0) years. Increasing radiation dose was associated with increased risk of meningioma (EOR/Gy, 1.44; 95% CI, 0.62-3.61), and there was no evidence of departure from linearity (P = .90). Compared with survivors who were not exposed to radiation therapy, those who received doses of 24 Gy or more had more than 30-fold higher odds of meningioma (OR, 33.66; 95% CI, 14.10-80.31). The radiation dose-response association was significantly lower among patients treated at age 10 years or older compared with those treated before age 10 years (EOR/Gy, 0.57; 95% CI, 0.18-1.91 vs 2.20; 95% CI, 0.87-6.31; P for heterogeneity = .03). Risk associated with radiation remained significantly elevated 30 years after exposure (EOR/Gy, 3.76; 95% CI, 0.77-29.15). We found an increased risk of meningioma among children who had received methotrexate (OR, 3.43; 95% CI, 1.56-7.57), but no evidence of a dose-response association or interaction with radiation dose.Conclusions and RelevanceThese findings suggest that the meninges are highly radiosensitive, especially for children treated before age 10 years. These results support the reduction in whole-brain irradiation over recent decades and the prioritization of approaches that limit radiation exposure in healthy tissue for children. The persistence of elevated risks of meningiomas for 30 years after cranial radiotherapy could help inform surveillance guidelines.

PURPOSE Fundamental gaps in knowledge regarding the risk of subsequent neoplasms (SNs) in children with pathogenic neurofibromatosis type 1 (NF1) variants exposed to radiation and/or alkylator chemotherapy have limited the use of these agents. METHODS We addressed these gaps by determining the SN risk in 167 NF1-affected versus 1,541 non–NF1-affected 5-year childhood cancer survivors from the Childhood Cancer Survivor Study and 176 nonoverlapping NF1-affected individuals with primary tumors from University of Alabama at Birmingham and Children’s Hospital of Philadelphia exposed to radiation and/or chemotherapy. Proportional subdistribution hazards multivariable regression analysis was used to examine risk factors, adjusting for type and age at primary tumor diagnosis and therapeutic exposures. RESULTS In the Childhood Cancer Survivor Study cohort, the 20-year cumulative incidence of SNs in NF1 childhood cancer survivors was 7.3%, compared with 2.9% in the non-NF1 childhood cancer survivors ( P = .003), yielding a 2.4-fold higher risk of SN (95% CI, 1.3 to 4.3; P = .005) in the NF1-affected individuals. In the University of Alabama at Birmingham and Children’s Hospital of Philadelphia cohort, among NF1-affected individuals with a primary tumor, the risk of SNs was 2.8-fold higher in patients with irradiated NF1 (95% CI, 1.3 to 6.0; P = .009). In contrast, the risk of SNs was not significantly elevated after exposure to alkylating agents (hazard ratio, 1.27; 95% CI, 0.3 to 3.0; P = .9). CONCLUSION Children with NF1 who develop a primary tumor are at increased risk of SN when compared with non-NF1 childhood cancer survivors. Among NF1-affected children with a primary tumor, therapeutic radiation, but not alkylating agents, confer an increased risk of SNs. These findings can inform evidence-based clinical management of primary tumors in NF1-affected children.

PURPOSE Female survivors of childhood cancer have a high risk of subsequent breast cancer. We describe the ensuing risk for mortality and additional breast cancers. PATIENTS AND METHODS Female participants in the Childhood Cancer Survivor Study, a cohort of 5-year survivors of cancer diagnosed between 1970 and 1986 before age 21 years, and subsequently diagnosed with breast cancer (n = 274; median age at breast cancer diagnosis, 38 years; range, 20 to 58 years) were matched to a control group (n = 1,095) with de novo breast cancer. Hazard ratios (HRs) and 95% CIs were estimated from cause-specific proportional hazards models. RESULTS Ninety-two childhood cancer survivors died, 49 as a result of breast cancer. Overall survival after breast cancer was 73% by 10 years. Subsequent risk of death as a result of any cause was higher among childhood cancer survivors than among controls (HR, 2.2; 95% CI, 1.7 to 3.0) and remained elevated after adjusting for breast cancer treatment (HR, 2.4; 95% CI, 1.7 to 3.2). Although breast cancer–specific mortality was modestly elevated among childhood cancer survivors (HR, 1.3; 95% CI, 0.9 to 2.0), survivors were five times more likely to die as a result of other health-related causes, including other subsequent malignant neoplasms and cardiovascular or pulmonary disease (HR, 5.5; 95% CI, 3.4 to 9.0). The cumulative incidence of a second asynchronous breast cancer also was elevated significantly compared with controls ( P < .001). CONCLUSION Mortality after breast cancer was higher in childhood cancer survivors than in women with de novo breast cancer. This increased mortality reflects the burden of comorbidity and highlights the need for risk-reducing interventions.

Background: Subsequent thyroid cancer (STC) is one of the most common malignancies in childhood cancer survivors. We aimed to evaluate the polygenic contributions to STC risk and potential utility in improving risk prediction. Methods: A polygenic risk score (PRS) was calculated from 12 independent SNPs associated with thyroid cancer risk in the general population. Associations between PRS and STC risk were evaluated among survivors from St. Jude Lifetime Cohort (SJLIFE) and were replicated in survivors from Childhood Cancer Survivor Study (CCSS). A risk prediction model integrating the PRS and clinical factors, initially developed in SJLIFE, and its performance were validated in CCSS. Results: Among 2,370 SJLIFE survivors with a median follow-up of 28.8 [interquartile range (IQR) = 21.9–36.1] years, 65 (2.7%) developed STC. Among them, the standardized PRS was associated with an increased rate of STC [relative rate (RR) = 1.57; 95% confidence interval (CI) = 1.24–1.98; P < 0.001]. Similar associations were replicated in 6,416 CCSS survivors, among whom 121 (1.9%) developed STC during median follow-up of 28.9 (IQR = 22.6–34.6) years (RR = 1.52; 95% CI = 1.25–1.83; P < 0.001). A risk prediction model integrating the PRS with clinical factors showed better performance than the model considering only clinical factors in SJLIFE (P = 0.004, AUC = 83.2% vs. 82.1%, at age 40), which was further validated in CCSS (P = 0.010, AUC = 72.9% vs. 70.6%). Conclusions: Integration of the PRS with clinical factors provided a statistically significant improvement in risk prediction of STC, although the magnitude of improvement was modest. Impact: PRS improves risk stratification and prediction of STC, suggesting its potential utility for optimizing screening strategies in survivorship care.

Background Human papillomavirus (HPV)-associated subsequent malignant neoplasms (SMNHPV ) in childhood cancer survivors are poorly understood. Methods The cumulative risk of SMNHPV was assessed among 24,363 Childhood Cancer Survivor Study participants. Standardized incidence ratios (SIRs) and absolute excess risk were calculated using age-matched, sex-matched, and calendar year rates from the Surveillance, Epidemiology, and End Results program. Poisson regression models identified SMNHPV risk factors, evaluating relative SIRs (rSIR) and 95% confidence intervals (95% CIs). Results In total, 46 survivors developed an SMNHPV (median age, 31 years [range, 10-56 years]; median time from primary cancer, 21 years [range, 9-35 years]). SMNHPV sites included oropharynx (N = 44), anorectum (N = 6), uterine cervix (N = 2), and vulva (N = 2). The 33-year cumulative incidence was 0.3% (95% CI, 0.2%-0.4%), and the SIR was nearly 3-fold that of the general population (SIR, 2.86; 95% CI, 2.05-4.00). Female survivors were not at increased risk of cervical or vulvar cancers compared with the general population. All survivors had an elevated risk of oropharyngeal SMNHPV (males: SIR, 4.06; 95% CI, 2.37-6.97; females: SIR, 8.44; 95% CI 4.88-14.61) and anorectal SMNHPV (males: SIR, 13.56; 95% CI, 5.09-36.13; females: SIR, 9.15; 95% CI, 2.29-36.61). Males (vs females: rSIR, 1.99; 95% CI, 1.00-3.94); head, neck, and pelvic radiotherapy doses >3000 centigray (vs none: rSIR, 2.35; 95% CI, 1.11-4.97); and cisplatin-equivalent doses >400 mg/m2 (vs none: rSIR, 4.51; 95% CI, 1.78-11.43) were associated with increased SMNHPV SIRs in multivariable analysis. Conclusions Childhood cancer survivors are at increased risk for SMN in sites susceptible to HPV-associated malignancies. Further research examining HPV in the etiology of SMN and the promotion of HPV vaccination and surveillance guidelines for SMNHPV in cancer survivors is warranted.

PURPOSE Women treated with chest radiation for childhood cancer have one of the highest risks of breast cancer. Models producing personalized breast cancer risk estimates applicable to this population do not exist. We sought to develop and validate a breast cancer risk prediction model for childhood cancer survivors treated with chest radiation incorporating treatment-related factors, family history, and reproductive factors. METHODS Analyses were based on multinational cohorts of female 5-year survivors of cancer diagnosed younger than age 21 years and treated with chest radiation. Model derivation was based on 1,120 participants in the Childhood Cancer Survivor Study diagnosed between 1970 and 1986, with median attained age 42 years (range 20-64) and 242 with breast cancer. Model validation included 1,027 participants from three cohorts, with median age 32 years (range 20-66) and 105 with breast cancer. RESULTS The model included current age, chest radiation field, whether chest radiation was delivered within 1 year of menarche, anthracycline exposure, age at menopause, and history of a first-degree relative with breast cancer. Ten-year risk estimates ranged from 2% to 23% for 30-year-old women (area under the curve, 0.63; 95% CI, 0.50 to 0.73) and from 5% to 34% for 40-year-old women (area under the curve, 0.67; 95% CI, 0.54 to 0.84). The highest risks were among premenopausal women older than age 40 years treated with mantle field radiation within a year of menarche who had a first-degree relative with breast cancer. It showed good calibration with an expected-to-observed ratio of the number of breast cancers of 0.92 (95% CI, 0.74 to 1.16). CONCLUSION Breast cancer risk varies among childhood cancer survivors treated with chest radiation. Accurate risk prediction may aid in refining surveillance, counseling, and preventive strategies in this population.

PURPOSE Risk-stratified therapy, which modifies treatment on the basis of clinical and biologic features, has improved 5-year overall survival of childhood acute lymphoblastic leukemia (ALL) to 90%, but its impact on long-term toxicity remains unknown. METHODS We assessed all-cause and health-related late mortality (including late effects of cancer therapy), subsequent malignant neoplasms (SMNs), chronic health conditions, and neurocognitive outcomes among 6,148 survivors of childhood ALL (median age, 27.9 years; range, 5.9-61.9 years) diagnosed between 1970 and 1999. Therapy combinations and treatment intensity defined 6 groups: 1970s-like (70s), standard- or high-risk 1980s-like (80sSR, 80sHR) and 1990s-like (90sSR, 90sHR), and relapse/transplantation (R/BMT). Cumulative incidence, standardized mortality ratios, and standardized incidence ratios were compared between treatment groups and with the US population. RESULTS Overall, 20-year all-cause late mortality was 6.6% (95% CI, 6.0 to 7.1). Compared with 70s, 90sSR and 90sHR experienced lower health-related late mortality (rate ratio [95% CI]: 90sSR, 0.2 [0.1 to 0.4]; 90sHR, 0.3 [0.1 to 0.7]), comparable to the US population (standardized mortality ratio [95% CI]: 90sSR, 1.3 [0.8 to 2.0]; 90sHR, 1.7 [0.7 to 3.5]). Compared with 70s, 90sSR had a lower rate of SMN (rate ratio [95% CI], 0.3 [0.1 to 0.6]) that was not different from that of the US population (standardized incidence ratio [95% CI], 1.0 [0.6 to 1.6]). The 90sSR group had fewer severe chronic health conditions than the 70s (20-year cumulative incidence [95% CI], 11.0% [9.7% to 12.3%] v 22.5% [19.4% to 25.5%]) and a lower prevalence of impaired memory (prevalence ratio [95% CI], 0.7 [0.6 to 0.9]) and task efficiency (0.5 [0.4 to 0.7]). CONCLUSION Risk-stratified therapy has reduced late morbidity and mortality among contemporary survivors of standard-risk ALL, represented by 90sSR. Health-related late mortality and SMN risks among 5-year survivors of contemporary, standard-risk childhood ALL are comparable to the general population.

Introduction: Higher BMI at ALL diagnosis is associated with an increased risk of post-induction residual leukemia (Orgel, Blood 2014) and relapse (Butturini, JCO 2007). However, children may experience significant changes in BMI during the pre-maintenance phases of ALL treatment (Withycombe, Pediatr Blood Cancer 2009), necessitating an examination of the association between BMI during maintenance and relapse risk. We hypothesized that higher BMI during maintenance would be associated with a greater risk of relapse. We also explored the association between BMI and red cell thioguanine (TGN) levels to understand whether BMI-associated variations in TGN biodistribution explained the BMI-relapse association. Methods: We used data from COG-AALL03N1 (primary aim was 6MP adherence) to examine the association between BMI during maintenance and relapse risk. Eligibility for enrollment on AALL03N1 included age ≤21y at ALL diagnosis and receiving maintenance therapy in first remission. The current analysis was limited to patients with wild-type thiopurine methyltransferase genotype. BMI (exposure variable) was calculated as sex- and age-based percentile per CDC normative data, and operationalized as normal/underweight [ Results: The sociodemographic and disease characteristics of the 676 study participants are summarized in the Table. Median BMI%ile was 88.5 (range, 0-100); normal/underweight: 43%, overweight/obese: 45%, and morbidly obese: 12%. As shown in the Figure, cumulative incidence of relapse at 2y from start of maintenance therapy was significantly greater among patients with morbid obesity (11.9±4.3%) when compared to those who were overweight/obese (5.4±1.6%) and underweight/normal weight (4.1±1.4%). After adjusting for the variables listed above, we found that patients with morbid obesity had a 3.2-fold greater hazard of relapse (95%CI=1.4-7.5, P=0.008) when compared to patients who were normal/underweight. After adjusting for age at enrollment, sex, race/ethnicity, 6MPDI, and time from initiation of maintenance, patients with morbid obesity had lower mean red cell TGN levels compared to normal/underweight patients (mean difference: -27.2±7.4 pmol/8 x 10 8 erythrocytes, P=0.0002). However, inclusion of TGN in the model did not alter the association between BMI and hazard of relapse (HR=3.8, 95%CI, 1.6-9.0, P=0.003). These findings did not change after adjusting for 6MP adherence in the sub-cohort with available adherence data (n=435). Conclusion: Morbid obesity during maintenance for childhood ALL is associated with relapse as well as lower systemic exposure to 6MP. However, lower TGN levels do not explain the relation between BMI and relapse risk. Therefore, there is a need to understand the mechanism of the relation between morbid obesity during maintenance and relapse risk in children with ALL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Purpose Survivors of childhood cancer treated with cranial radiation therapy are at risk for subsequent CNS tumors. However, significant interindividual variability in risk suggests a role for genetic susceptibility and provides an opportunity to identify survivors of childhood cancer at increased risk for these tumors. Methods We curated candidate genetic variants from previously published studies in adult-onset primary CNS tumors and replicated these in survivors of childhood cancer with and without subsequent CNS tumors (82 participants and 228 matched controls). We developed prediction models to identify survivors at high or low risk for subsequent CNS tumors and validated these models in an independent matched case-control sample (25 participants and 54 controls). Results We demonstrated an association between six previously published single nucleotide polymorphisms (rs15869 [ BRCA2], rs1805389 [ LIG4], rs8079544 [ TP53], rs25489 [ XRCC1], rs1673041 [ POLD1], and rs11615 [ ERCC1]) and subsequent CNS tumors in survivors of childhood cancer. Including genetic variants in a Final Model containing age at primary cancer, sex, and cranial radiation therapy dose yielded an area under the curve of 0.81 (95% CI, 0.76 to 0.86), which was superior ( P = .002) to the Clinical Model (area under the curve, 0.73; 95% CI, 0.66 to 0.80). The prediction model was successfully validated. The sensitivity and specificity of predicting survivors of childhood cancer at highest or lowest risk of subsequent CNS tumors was 87.5% and 83.5%, respectively. Conclusion It is possible to identify survivors of childhood cancer at high or low risk for subsequent CNS tumors on the basis of genetic and clinical information. This information can be used to inform surveillance for early detection of subsequent CNS tumors.